Diamond die driller



Marh 25, 1947. F. CROSSMAN UAL 2,417,811

DIAMOND DIE DRILLER i Filed-Feb. 2e, 1945 2 sheets-sheet 1 'Il Il..

March 25, 1947- F. CRosSMAN Erm. v 2,417,811

DIAMOND DIE DRILLER Filed Feb.' 2e, 1945 i 2 sheets-sheet 2 Hymnen! Patented Mar. 25, 1947 DIAMOND DIE DRILLER Fred Crossman, Earl A. Southam and George J.

Ruhl, Cleveland, Ohio, assignors to The Lindsay Wire Weaving Company, Cleveland, Ohio, a corporation of Ohio Application February 26, 1945, Serial No. 579,834

7 Claims.

y of an inch in diameter.

Diamond die drilling machine having a vertically disposed drilling spindle have heretofore been used, but the machines have been somewhat complex in construction and have not only involved a problem of maintenance and repair, but also one of accuracy and selectivity in control of the moving parts. The drilling needle heretofore used has had a rotating and reciprocating motion imparted thereto, but the reciprocating motion has been uniformly regular in the time of contact with and withdrawal from the work. The purpose of the reciprocation is to afford an opportunity for the fluid-like abrasive material to enter the cavity in the diamond during the drilling operation, hence, it is desirable to be able to vary the period of contact and withdrawal of the needle from the work so as to impart a vibratory motion to the needle that is more effective in attaining the desired abrasive action than is possible with a uniformly regular period of contact and withdrawal.

In operating prior machines, as aforesaid, the needle must be frequently removed for dressing the point, and for such purpose considerable time has heretofore been lost in waiting for the needle to cease rotating under the influence of the momentum of the moving parts, and when it is considered that an operator is usually in charge of a battery of drilling machines, any time consumed in awaiting stoppage of rotation becomes an appreciable item in the course of a working day.

An object of the present invention is to make a diamond die drilling machine which is capable of drilling small holes having a diameterof the order heretofore set forth, and in accomplishing such purpose in a more satisfactory manner by reducing the working parts, by increasing the selectivity of control of the needle reciprocation, and by reducing the time required to change the needle whenever the need for dressing the point thereof becomes apparent. In this way, an operator may be in charge of a larger number of machines and the accuracy of the Work may be greatly improved.

Referring now to the drawings, Fig. 1 is aside view partly in section of a machine embodying the present invention; Fig.,2 is a top plan view of the machine; Fig. V3 is a section taken on a plane indiing plates I I.

' cated by the line 3--3 in Fig. 1; Fig. 4 is a section taken on a plane indicated by the line 4-4 in Fig. 2; Fig. 5 is a section taken on a plane indicated by the line 5-5 in Fig. 4, and Fig. 6 is a vertical section taken through the needle driving mechanism. Y

We have shown our diamond drilling mechanism as being mounted upon a frame which includes a topframe plate I0 and a pair of horizontally disposed bearing plates II which are spaced from each other and are adapted to be held together in any suitable manner, as bythe spacing members I2 and' I3. The frame may support a plurality of drilling units but only one is illustrated in the drawings, it being understood that the construction of all are identical to that illustrated. Each drilling unit includes a rotatable work-supporting table vI5 which may be supported by a vertically disposed shaft I6 that is journalled in bearings I'I in the respective bear- The work table mave have a smooth upper surface on which a work xture I8 that carries the diamond to be drilled may be positioned and centered with respect to the needle.

The work table may be rotated by any suitable source of power through a driving belt 20 which extends around a driving pulley 2l that is fixed to the shaft I6 intermediate the bearings I'I. In practice, the direction of drive is such that the work table rotates in a direction opposite to that of the drilling needle and at a slower speed.

The drilling mechanism is mounted on the upper frame plate I0 in such manner that the drill spindle and drill extend vertically. The mechanism includes a cylindrical frame or housing 25 which may be secured to the base plate 26 which rests upon the frame plate I0 and is adjustably secured thereto. Mounted within the housing are a pair of spaced vertically aligned bearings, preferably of the precision ball type, each of which has an inner race 21 and an outer race 28. The latter races engage in the inner wall of the housing and are secured thereto in the customary manner, while the inner races have rigidly secured thereto a sleeve 29 which has an axially extending passageway through which the needle holder is adapted to extend. 'I'he passageway through the sleeve, as shown in Fig. 6, has a clearance with the needle holder or spindle 30 except at the end portions thereof whereV a close sliding t is provided by means of bushings 3l and 32 respectively.

The spindle 30 is preferably made of any suitable lightweight'material'and has its axis extending vertically. Moreover,v the spindle has such diameter that it will move freely in an axial direction through the bearings 3| and 32 under the influence of gravitation despite its lightness in weight. A needle 33 is mounted in a chuck 34 which is attached in any convenient manner to the lower end of the spindle.

By mounting the= bearings adjacent the 'end of the housing 25 and by applying a driving'rotational force intermediate the bearings, the spinclle is not subjected to driving strains, wherefore frictional drag of the Spindle in the bearingis eliminated, as Well as any misalignment of theY spindle that might be due to the'drive. The driving connection may comprise a p in- 35 which is shown as being rigidly carried by the sleeve adjacent the lower end thereof, and as being adapted to project into an axially extendingslot 35 in the spindle 30. The slot is open ,atA the lower end so that the spindle may be withdrawn whenever desired from the housing 25.

To rotate the sleeve 29, we have illustratedfav belt 45 which isadapted to bedriven by any suitable' source of power (not shown) and'which is arranged to extend aroundfthe sleeve-and to en- 'gage a groove 4I therein for eiecting a driving connection with the sleeve. In Fig. 6, thebelt is shown inengagement with an idler pulley 42 which rotates freely on the sleeve 25. In .such illustration, the sleeve is disconnected from` the driving belt, but the change from theidler pulley j to the driving groove 4I maybe effected by means a shoev 41`at the inner end thereof for engage-Y mentwiththe-sleeve.` f Y Normally the shoeris held out 'of contact with the sleeve by a spring 48', one. end of' which bears against the housingfandthe otheroi which bears against the head 49 of therod. Such head at the outer portionthereoi is;rounded;for engagement` byanV arm 5i! which is adapted toextend laterally ofv the lever 43, In the position shown in Fig. 6,- the armV 5U is in engagement with the central portionof the head 49 at which time the spring is compressed and the `shoe* is in braking engagement with the sleeve 29. At the same time, the shipper lever 43 is in `the position shown by the full lines in Fig. 1, and the belt 40 is thereby heldV on the idler pulley 42. When the shipper levery is moved to the broken line position 43A, however, the belt 40 is moved downwardlyA to the position 40A from the idler pulley 42 onto the sleeve groove 4l, and the arm 50 is moved to the broken line position 50A, thereby allowing the spring 48 to release thebrake sol that a driving connection is made to the sleeve immediately upon shifting ofthe lever 43..

To effect a reciprocating action of the needle at selected intervals, we utilize a lever 55 which is pivoted at 55 to a block 51. The lever hasia forked end'58 ior engagementbeneath a collar 59 on the spindle V3i), and has the other end curved,

.asY att, for engagement bycams 6I that are shown as being carried on the peripheral edge of a disc 52 that is fixed to a shaft 63., Theshaft in'turn is shown asbeing` journalled in bearings 6d 4and 65, and as 'beingfdriven bya' belt 6B that extends arounrLa pulley; dlthatisfsliown as' being xed to the shaft. The belt may be driven from any suitable source of power (not shown) The cams 5i operate to effect intermittent rocking motion of the lever 55 about the pivot 56, and the position of the pivot is adjusted so as to impart a reciprocating action to the needle spindle, consequent upon contact of the various cams with the curved end 50 of the lever-55. The cams may be mounted at spaced intervals on the disc, `suitable `for any desired number of impulses to Y beiimparted to the lever, per revolution of the disc 52. Thus, in the form shown, three im pulsesfare made per revolution, with two of the cams being spaced 180 apart and the third cam Vbeing spaced `fr0m the other cams. This arrangement will then give a dwell for one-half revolution ofn the disc and thereby allow sufiicient time for the abrasive material to collect around the point of the needle.

To adjust the position of the pivot block 51, the block is illustrated as having a threaded passageway forY engaging a threaded rod'ii. The rod has a knob 59'at' the end thereof and extends through an Yopening in a bar 'Iii that connects the tops of posts 'Il which are'illustrated as circular rods that act as guides for the block 51. For such purpose, opposing sides of the block are indented, as at 12 and.'l3,- as is shown in Fig. 5. Thespring i5 operates to urge the block 5'l up; wardly so as to hold'a crosspin 'I5 on the rod 58 in engagement with the undersidev of the bracket l5. Thus, whenever the knob 69 is turned, the vertical position of the block 51 and, therefore, of the pivot 5E, is adjusted with respect to a plate 'il that projects laterally from the housing 25 and carries the adjusting mechanism for the pivot 55, as well as the cam mechanism for operating the lever 55. Any adjustment vertically of the pivot altersthe degree of recprocation imparted to the needle spindle. upon actuation thereof by contact between the cam 6| and the lever 55.

The drill spindle housing is arranged to be moved to align the drill with the work. To this end, the housing supporting plate 261s slidably mounted upon the frame member l0 and the position of the mounting is adjustable by a pair of eccentric cams 8D and 8l, while the table is secured in adjusted position by a clamping nut, indicated at 82;

The mechanism which We have illustratedv will operate in a satisfactory manner to drill holes of relatively small diameter in diamonds with a high degree of precision. At the same time, it will permit selective 'control of' the timing and extent .of reciprocation of the needle during the drilling operation. The mechanism is simple and compact and lends itself to use in multiple ar rangement, thereby enabling one operator to'su pervise the drilling of a largenurnber of dies, and to stop the operation qui :kly on any particular die without necessitating a loss of time inA adjusting the needle for dressing the point, or for replacing it withone of different size, as conditions may require.

We claim:

1. A machine for drilling comparatively small holes in work pieces, comprising in combination, a housing, spaced bearings carried by the housing, a sleeve interconnecting the bearings and having a belt groove thereon, an idler pulley journalled on the sleeve, a driving belt, means for shiftingv the belt between the pulley4 and sleeve groove, and a drill spindle extending through the sleeve and having asplined connectiontherewith, wherebylthe spindle may be rotated butfmaybe withdrawn vertically from the machine Without` disturbing the driving connection therefor.

2. A machine for drilling comparatively small holes in work pieces, comprising in combination, a housing, spaced bearings carried by the housing, a sleeve interconnecting the bearings, a drill spindle extending through the sleeve and being freely slidable axially therein, said sleeve having a splined connection with the spindle whereby the spindle maybe rotated but may be Withdrawn vertically from the machine without disturbing the driving connection therefor, a driving belt extending around the sleeve intermediate said bearings, an idler pulley journalled on the sleeve, means for shifting the belt between the sleeve and pulley, and braking mechanism operable automatically with reference to the sleeve upon actuation of said means.

3. A machine for drilling comparatively small holes in work pieces, comprising in combination, a. frame, spaced bearings carried by the frame, a sleeve journalled in said bearings, a drill spindle extending through the sleeve and being freely slidable axially therein, means for rotating the sleeve, said means including a belt adapted to be moved into driving engagement therewith, an idler pulley journalled on the sleeve and adapted also to receive said belt, said spindle having a splined driving connection with the sleeve so as to permit withdrawal of the spindle from the sleeve, a lever tted to the housing and having belt-engaging means thereon for shifting the belt between the sleeve and idler pulley, and means actuated upon movement of the lever to engage the sleeve frictionally so as to arrest rotation thereof upon shifting of the belt from engagement with the sleeve onto the idler pulley.

4. A machine for drilling comparatively small holes in work pieces, comprising in combination, a frame, spaced bearings carried by the frame, a sleeve journalled in :the bearings, a drill spindle mounted in said sleeve with its axis extending vertically, said spindle being freely slidable axially in said sleeve and having a detachable driving connection therewith, a belt for rotating the sleeve, a pulley wheel journalled on the sleeve, means for shifting the belt between fthe sleeve and wheel, the spindle having a collar thereon,

'a rockable lever adapted to engage the collar, a

rotatable member having cam means .thereon for engaging the lever at prearranged intervals, and means for shifting the position of the lever so as to vary the extent of movement of the collarengaging portion thereof.

5. A machine for drilling comparatively small holes in work pieces, comprising in combination, a frame, spaced bearings carried by the frame, a sleeve journalled in the bearings, a drill spindle freely slidable axially in the sleeve and having a driving connection therewith whereby the spindle may be rotated but may be withdrawn vertically from the machine without disturbing the driving connection therefor, said sleeve having a peripheral groove therein, an idler pulley journalled on the sleeve adjacent said groove, a driving belt, means for shifting the belt between the groove and the pulley, a braking device movably mounted on the frame and adapted to engage the sleeve automatically upon actuation of the shifting means, means for imparting a reciprocating motion to the spindle during rotation thereof, said means including a lever pivoted intermediate the ends thereof, said lever having one end thereof engaging the spindle, cam means adapted to engage the other end of the lever, and means for adjusting the position of the pivot vertically with respect to the spindle whereby the extent of axial movement of the spindle may be varied without varying the throw of the cam means.

6. A machine for drilling comparatively small holes in work pieces, comprising in combination, a frame, spaced bearings carried by the frame, a sleeve journalled in said bearings, a drill spindle mounted in the sleeve and being freely slidable axially therein, means for effecting a driving connection between the sleeve and spindle, whereby the spindle may be rotated but may be withdrawn vertically from the machine without disturbing the driving connection therefor, belt means for rotating the sleeve, an idler pulley associated with the sleeve and onto which the belt may be shifted, said idler pulley and belt being disposed between the bearings, a spring pressed plunger slidably mounted in the frame and having a brake shoe thereon adapted to engage the sleeve, means for shifting the position of the belt between the pulley and sleeve, a member for automatically actuating said plunger to eiect a braking action on said sleeve consequent upon shifting of the belt from the sleeve onto the pulley, said spindle having a collar thereon, a lever having a. forked end for receiving the spindle and engaging the collar, said lever having a pivot intermediate the ends thereof, means for shifting the position of the lever vertically with respect to the frame, and means adapted to engage the other end of said lever, said means including a rotatable disc, and cam members mounted at spaced intervals thereon.

7. A machine for drillingcomparatively small holes in work pieces comprising in combination, a frame, spaced bearings carried by the frame, a sleeve journalled in said bearings, a drill spindle extending through said sleeve and being freely slidable axially therein, means disposed intermediate the bearings for rotating the sleeve, means for effecting a driving connection between the sleeve and spindle, and means for reciproeating the spindle during the rotation thereof, said means including a rockable lever pivoted intermediate the ends thereof, means for shifting the pivot vertically with reference to the frame, said lever having one end thereof engaging the spindle, and cam means engaging the other end of the lever, said cam means comprising a rotatable disc having protuberances disposed at spaced intervals on the periphery thereof.

FRED CRO-SSMAN. EARL A. SOUTHAM. GEORGE J. RUHL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

